Central locking dead and Drivers Door electrics not working

[DavidS2]

Hello Brains Trust !
I have a 1994 Elan S2 and the drivers door electrics don’t work - (eg) when I open the drivers door no interior lights come on. But open the passengers side and lights work fine. Also central locking on either side doesn’t work at all !? Any advice is greatly appreciated.
Thanks .. David

[Saltire]

David, the interior lights are driven from the door by a switch inside the door itself (not a switch on the door jamb as is the case with many other cars). To get at it, you’ll need to remove the door card, which is not hard but is rather long-winded - many screws. Lots of posts on here describing how it’s done.

The central locking on the S2 (SE and NA are different) on my UK car is driven by the alarm system. However, I note that you’re in Australia, and I’m not sure whether ROW cars had the same alarm, so treat this information with caution. Setting the alarm sends a ‘lock’ pulse to the door lock mechanism, and vice versa when it’s unlocked. On a UK car, I’d be checking for electrical continuity in that circuit. What kind of alarm system (if any) does your car have?

It sounds to me as though the two problems could be related, and I suspect a previous owner may have “improved” the electrics Has this issue developed recently, or have you always had it?

By the way, manuals and circuit diagrams are always available under the ‘Manuals’ tab on the menu at the top of this page

[Rambo]

This might help?

http://wikilec.com/images/e/e5/MJ25-10_ ... _Lamps.gif

[Saltire]

This might help?

http://wikilec.com/images/e/e5/MJ25-10_ ... _Lamps.gif

Mark, pardon me for jumping in . . .

David, just be aware that there’s no interior light delay module on the S2. There’s a direct connection between the interior lamps and the light switch, giving an earth path if the switch is on. (Thought: do the interior lights operate normally if you pull out the light switch?)

[Rambo]

This might help?

http://wikilec.com/images/e/e5/MJ25-10_ ... _Lamps.gif

Mark, pardon me for jumping in . . .

David, just be aware that there’s no interior light delay module on the S2. There’s a direct connection between the interior lamps and the light switch, giving an earth path if the switch is on. (Thought: do the interior lights operate normally if you pull out the light switch?)

No problems Jonathan. I hadn't realised there was no light delay module in the S2 (only ever had 3 SE's ) or that the circuit diagram pertained to an SE

[378S2]

Hi David - I think that I own your old S2 (number 378). I'd love to chat to you about the cars history - there wasn't a lot of history with it when I got it. It's been a wonderful car so if it was you that did all the restoration work, thank you!

[Tuga2112]

do the windows work ? what about the wing mirror ?
if none works. could be something as simple as the harness connector not being plugged.

[DavidS2]

Many thanks all for the great advice to fix the issue - seems my alarm did at some stage prior to me link to the central
Locking function - and the one press of the fob would do both. Sadly today my fob just seems to set the alarm (hazards flash when fob pressed) but central locking doesn’t work. Not sure if it’s related but when u open drivers door internal lights don’t come on, but do for passengers door !? Bit baffling ?

[DavidS2]

Hi 378s2 (George) - great to chat today and glad your enjoying my old S2, awesome car. Hope you liked the photos etc I sent you - am sure you will have many great drives ahead - we all love these brilliant Elan’s here (despite the occasional issues .. Dave

[Tuga2112]

Not sure if it’s related but when u open drivers door internal lights don’t come on, but do for passengers door !? Bit baffling ?

not baffling.
door latch provides a grounding point for the interior lights. both doors do that. and your car has had the wiring fiddled with from a "professional" electrician in the past. good chance he used this wire as a signal for the alarm to know the door is open.

does the alarm go off when its set and the driver door is opened, but that doesnt happen with the passenger door ?

either way.
the central locking system is very well documented in the electrical manual. and the circuit diagrams are very good as well. (not as good as toyota's from the same era, but you cant expect that level of quality on Lotus's budget)
http://www.lotusm100.com/manuals/Elan-M ... ual-v6.pdf


i bet your alarm instalation is very intrusive to the car's electrical system.

you will need to assume the lotus position. and check/trace the wires from the driver's side door harness
your looking for 3 yellow wires,
one with a red trace (used to determine if the door locks have been operated)
pink and blue trace work as a pair. they operate on a 12v to 0v and vice versa with forces the solenoids to lock and unlock the doors.

if you find out which ones of them have been re-directed to the alarm. you can start to un-modify your car.

the correct procedure to wire the door locks is to only connect the yellow-red wire to the alarm. and both ends of your cut should be connected to 2 different wires in the alarm box.
if the alarm is tapping into the yellow-pink and yellow-blue wires, you should have noticed in the past that one door lock operated before the other.

electrical issues caused by poor alarm instalations are common in cars from the 90s' but i suspect your situation is more of a alarm that is internally broken, but there are a few unaswered questions pending. which could lead to wiring problems instead


red wire with grey (slate) trace is the line used by the ajar switch (the ones that drives the automagic unlock functionality when you lock the doors but the doors are actually open)

[Saltire]

Not sure if it’s related but when u open drivers door internal lights don’t come on, but do for passengers door !? Bit baffling ?

the central locking system is very well documented in the electrical manual. and the circuit diagrams are very good as well.

i bet your alarm instalation is very intrusive to the car's electrical system.

you will need to assume the lotus position. and check/trace the wires from the driver's side door harness
your looking for 3 yellow wires,
one with a red trace (used to determine if the door locks have been operated)
pink and blue trace work as a pair. they operate on a 12v to 0v and vice versa with forces the solenoids to lock and unlock the doors.

red wire with grey (slate) trace is the line used by the ajar switch (the ones that drives the automagic unlock functionality when you lock the doors but the doors are actually open)

Well, only up to a point

We’re talking about an S2 here. The S2 doesn’t have a separate central locking module, and isn’t as well documented in the manuals. Been there, done that, fitted the alarm

In my doors,the yellow/red wire is looped back from the factory and not connected inside the door, and both the original (Gemini Aquila 5160T) and my replacement (Toad Ai606T2) alarms connect to the yellow pink and yellow/black wires to operate the door lock motors. Both door locks operate simultaneously using the alarm fob either Gemini fob or Toad fob).

I still think you need to do a systematic fault find in the drivers door, using a multimeter and starting with the door ajar switch